Rxivist logo

S3norm: simultaneous normalization of sequencing depth and signal-to-noise ratio in epigenomic data

By Guanjue Xiang, Cheryl A. Keller, Belinda Giardine, Lin An, Qunhua Li, Yu Zhang, Ross C Hardison

Posted 26 Dec 2018
bioRxiv DOI: 10.1101/506634 (published DOI: 10.1093/nar/gkaa105)

Quantitative comparison of epigenomic data across multiple cell types or experimental conditions is a promising way to understand the biological functions of epigenetic modifications. However, differences in sequencing depth and signal-to-noise ratios in the data from different experiments can hinder our ability to identify real biological variation from raw epigenomic data. Proper normalization is required prior to data analysis to gain meaningful insights. Most existing methods for data normalization standardize signals by rescaling either background regions or peak regions, assuming that the same scale factor is applicable to both background and peak regions. While such methods adjust for differences in sequencing depths, they do not address differences in the signal-to-noise ratios across different experiments. We developed a new data normalization method, called S3norm, that normalizes the sequencing depths and signal-to-noise ratios across different data sets simultaneously by a monotonic nonlinear transformation. We show empirically that the epigenomic data normalized by our method, compared to existing methods, can better capture real biological variation, such as impact on gene expression regulation.

Download data

  • Downloaded 876 times
  • Download rankings, all-time:
    • Site-wide: 22,484
    • In bioinformatics: 2,734
  • Year to date:
    • Site-wide: 39,859
  • Since beginning of last month:
    • Site-wide: 47,129

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide


Sign up for the Rxivist weekly newsletter! (Click here for more details.)